Wrapping machine



ApriIZS, 1968 H. L. BYLAND WRAPPING MACHINE 7 Sheets-Sheet 1.

Filed Dec. 7. 1964 INVENTOR. HOZMW V f f i April 3, 1968 H. BYLAND3,378,990

WRAPPING MACHINE Filed Dec. 7. 1964 '7 Sheets-Sheet 2 INVEN TOR.

HM EM April 23, 1968 H. L. BYLAND WRAPPING MACHINE 7 Sheets-Sheet 5Filed Dec. 7. 1964 INVENTOR.

April 23, 1968 H. L. BYLAND 3 WRAPPING MACHINE Fiied Dec. 7. 1964 7Sheets-Sheet 4 INVENTOR.

April 23, 1968 H.'L. BYLAND 3,378,990

WRAPPING MACHINE Filed Dec. 7. 1964 7 Sheets-Sheet 5 INVENTOR.

April 23, 1968 H. L. BYLAND 3,378,990

WRAPPING MACHINE INVENTOR.

. Q g Q wwkw April 23, 1968 H. BYLAND I WRAPPING MACHINE 7 Sheets-Sheet'7 Filed Dec. 7. 1964 I N VENTOR. W

M g d w e a Q 2 4 f 1 6 1 w M a .2 m M M fl 1 J 1 w J 1 2 6 /0 j 2 y w g5 w 64 1 i w 1 w a a 2 v United States Patent 3,378,990 WRAPPING MACHINEHenry Lowell Byland, 20 Berkshire Lane, Deerfield, Ill. 60015 Filed Dec.7, 1964, Ser. No. 416,504 13 Claims. (Cl. 53-206) ABSTRACT OF THEDISCLOSURE The machine for wrapping packages of the type including arectangular tray and an irregularly shaped content within the tray, suchas meat and the like, with a square sheet of heat scalable material,wherein the sheet is initially wrapped about the package with itsdiagonal axes generally coincident with the major and minor axes of thetray, and two opposite corners of the sheet are folded under and againstthe bottom of the tray and sealed together so that the sheet is securedproperly about the package with generally tubular extensions projectingat opposite sides, includes a pusher for advancing the package ininitially wrapped condition to a final wrapping position, a frontpivotally mounted tucking means engageable with the forward part of theunder portions of the projecting tubular wrapper to fold those partsupwardly against the side of the tray, rear tuckers connected to andmovable with the pusher and engageable with the rearward part of theunder portions of the projecting tubular wrapper to fold those partsupwardly against the sides of the tray. side folding blades withreentrant parts to fold the projecting tubular portions including thetucked forward and rearward parts over the front tuckers as the pusherand the rear tuckers are retracted, the front tuckers and the foldingblades being removed from the tucking and folding positions,respectively, without disturbing the tucked and folded tubular sheetportions, movable heat sealing frames including a curtain folding thetucked and folded sheet portions against the undersides of the traysubsequent to the removal of the front tuckers and the folding bladesand sealing them to the initially folded and sealed sheet portions, asingle track rotatable cam, an electric motor for driving the cam, andappropriate linkage connecting the cam track with the pusher, the fronttuckers, the rear tuckers, the folding blades, and the movable heatsealing means. i

The change in retail marketing of certain foods, such as meats andvegetables, to accommodate the self-service departments of the large orsupermarket stores, whether they be a part of a chain or independentlyowned, has created a demand for machines capable of wrapping packages ina manner whichpermits inspection while preventing contamination of theproduct. Many products, such as fruits, vegetables, and tubers, arepackaged in transparent bags. Meats are usually packaged in shallow,rectangular or square, lightweight, fiberboard trays which are wrappedand sealed in a wrapping of a transparent film. It is with this lattertype package that the present invention is concerned.

Machines have been designed, and some sold, which will package meats inshallow rectangular or square trays enclosed and sealed in transparentwrappings. Such machines have been complicated mechanisms which areinitially expensive and require constant maintenance. They are costly,and some take up substantial space. Since a large percentage of thistype of packaging is done in the retail store, it is in the interest ofthe retail merchant that the wrapping machine be as compact as possibleto conserve space, be adaptable for packages of various sizes, be simpleto operate, be of low cost, and be easy to service and maintain.

3,378,990- Patented Apr. 23, 1968 It is, therefore, a principal objectof the present invention to provide a new and improved wrapping machinehaving the foregoing advantages.

Another object is to provide a new and improved continuous method ofwrapping packages including a rectangular tray and irregularly shapedcontents with a square sheet of transparent and heat scalable material.

Another object is to provide new and improved method of wrappingpackages including a rectangular tray and irregularly shaped contentswith a square heat sealable sheet wherein the sheet is placed diagonallyover the tray and contents and two opposite corners are manually foldedunder the tray, overlapped and sealed together, and the remainingportions of the sheet are automatically tucked, folded, and sealed andthe wrapped package delivered without further manual handling.

Another object is to provide a new and improved wrapping machine havingonly two stations where the complete wrapping is effected, thusminimizing the machine size.

Another object is to provide a new and improved wrapping machine havinga first station where the operator places a square heat scalable sheetdiagonally over the tray and contents, folds diagonally opposite cornersunder the tray, and seals them together, and the machine tucks, folds,and seals the projecting portions of the sheet under the tray as thepackage is moved to and through a second station.

Another object is to provide a new and improved wrapping machine whereinthe mechanisms for advancing the package, tucking, and folding the sheetunder the package tray, and heat sealing overlapped portions of thesheet together are driven from a single cam element.

Another object is to provide a new and improved wrapping machine whichmay be used for wrapping packages with a large number of different heatscalable sheets, such as cellophane, polyethylene, polystyrene,polyvinyl chloride, and Pliofilm brand of a rubber hydrochloride.

Other objects and advantages will become apparent from the followingdescription taken in conjunction with the accompanying drawings, inwhich FIG. 1 is a plan view of the wrapping machine of the presentinvention;

FIG. 2 is a vertical sectional view, taken along the line 22 of FIG. 1,looking in the direction of the arrows, showing the positions of thepackage, tuckers, folders, and drive elements at the start of anoperation, with most of the machine elements shown in elevation;

FIG. 3 is a fragmentary vertical sectional view on an enlarged scale,taken substantially in the plane of FIG. 2, with the package at thefolding and sealing station immediately prior to having the foldersmoved to fold the wings of the wrapping sheet;

FIG. 4 is a fragmentary transverse sectional view on the scale of FIG.3, taken on the line 44 of FIG. 3, looking in the direction of thearrows, showing the cooperative positioning of the tuckers and foldersand part of the mechanism for operating the tuckers;

FIG. 5 is a fragmentary longitudinal sectional view, taken on the line5-5 of FIG. 4, looking in the direction of the arrows, showing thecooperative relationship of the front and rear tuckers;

FIG. 6 is a transverse sectional view, taken on the line 66 of FIGS. 1and 2, looking in the direction of the arrows, showing the machineposition immediately after the folders have folded the wrapping sheetwings and before the heat sealers have been moved through a heat sealingoperation;

FIG. 7 is an enlarged fragmentary transverse sectional view, taken inthe plane of FIG. 6, showing the heat sealers in advanced position;

FIG. 8 is an enlarged fragmentary sectional view, taken on the line 88of FIG. 1, looking in the direction of the arrows, showing the structurefor mounting and guiding one of the heat sealers;

FIG. 9 is an enlarged fragmentary sectional view, taken on the line 99of FIG. 1, looking in the direction of the arrows, showing the mechanismfor adjusting the spacing between the pairs of tuckers and folders toaccommodate different sizes of packages; and

FIG. 10 is an enlarged fragmentary sectional view, taken on the line10-10 of FIG. 3, looking in the direction of the arrows, illustratingdetails of the pusher for advancing the package.

General functions As noted previously herein in discussing the objectsand advantages of the new and improved package wrapping apparatus andmethod, the functioning of the apparatus is controlled by a single camelement. This cam element is prograrned or timed so that a completemachine cycle is divided into four parts corresponding to a one-quarterrotation of the cam, as will be set forth more fully hereinafter. It isadvantageous to an understanding of the machine operation to describethe four parts of a single machine cycle.

In the first quarter of the cycle, the package is advanced from thefirst station, at which the wrapping sheet is manually wrapped about thepackage of rectangular tray and contents in one direction and theoverlapping diagonnally oriented corners are heat sealed together, tothe second station, and during this movement the front and rear tuckerstuck the underside of the open tubular portion of the wrapping sheetagainst the sides of the tray. During this first quarter cycle thefolders are raised for the next operation on the package.

During the second quarter of the cycle, the folders are lowered to foldthe projecting wings of the wrapper sheet about the tuckers and to drawthe top of the sheet tightly about the contents of the package so thatas much air as is possible is excluded from the package and the contentsare made clearly visible to the prospective purchaser. During thissecond quarter of the cycle, the pusher which advanced the package fromthe first station to the second station and the rear tuckers isretracted. At the end of the folding operation, the folders depress thefront tuckers out of the Way of the heat sealing mechanism which isoperated in the last two cycle quarters.

During the third quarter of the cycle, the heat sealers are advancedwith the folders and front tuckers in the down position and they drawthe folded-down portion of the wrapping sheet in taut condition againstthe underside of the package tray and they seal together the overlappedportions of the wrapper and also seal them against the previously foldedunder and sealed wrapper portions.

During the fourth quarter cycle, the heat sealers are retracted and themachine is conditioned for a subsequent operation with the packagepusher and rear tuckers retracted, the folders lowered, and the fronttuckers positioned to be moved into tucking position as soon as thefolders are raised during the first quarter of the next succeedingmachine cycle.

In the drawings, the package is shown to be composed of a tray T made ofa pressed fiberboard material, contents C, and a wrapper W. The tray isshown as having low sides, but it may be a flat panel and its dimensionsmay vary widely from four inches square to nine inches by twelve inches.The wrapper may be made of any of a number of heat sealing materials,preferably transparent, and the wrapper may also include advertising orprinting and the like, accompanying the display of the contents. Thecontents include generally meat products such as poultry, roasts, chops,steaks, ground and sliced meats, sausages, and the like, usually ofirregular configuration, and among the harder contents to wrap are wholechickens, turkeys, and the like. The tray, when provided with sides,ordinarily is not more than one inch deep and frequently is less thanthat. It is designed for purpose of initially confining the productbeing marketed, with a substantial portion of the product to bedisplayed through the stretched wrapper. The various sizes and types oftrays and wrappers are well known in this art and do not form any partof the invention.

General assembly Referring to the drawings, and particularly to FIGS. 1,2, and 6, it will be observed that the wrapping machine 20 includes a.frame 22 comprised of a generally rectangular top frame 24, legs 26supported on conventional casters 28, and having an extension frame 30projecting from one side thereof as seen best in FIGS. 1, 2, and 3. Theframe includes bottom frame members 32 and longitudinally extendingintermediate support beams 34 and 36.

Supported by the extension frame structure 30 is a first station 38 atwhich the operator wraps the package of tray T and contents C with awrapper sheet W, preferably square, with the sheet W placed so that oneof its diagonal axes is transverse to the longitudinal axes of the trayand perpendicular to the path of movement of the tray and contents. Thepackage is transported to a second station 40 at which the package iscompleted. From the second station 40 the package is moved to an outlet42 which may comprise a basket, conveyor, or some other arrangement forcollecting the wrapped packages in accordance with the demands of theoperation.

Essentially, the machine 20 includes a stationary heat sealing element44 for manual use, a pusher mechanism 46, a tucker assembly 48, a folderassembly 50, a movable heat sealing mechanism 52, a power unit 54, and asequence control mechanism 56. The machine is electrically controlledand a start button is pressed to initiate the machine cycle and a limitswitch is tripped to terminate the cycle. The start button and itsswitch may be tripped as an incident to setting the package in front ofthe pusher mechanism and the limit switch opened when the sealingmechanism 52 has been withdrawn.

The power unit 54 includes an electric motor 58 which has a built-inspeed reduction and which drives an output sprocket 60, a chain 62, alarger sprocket 64, and a spring loaded detent clutch assembly 65 fixedto a shaft 66 journaled in bearings carried by the support beams 34 and36. The motor and gear reduction unit 58 is mounted on a platform 68which is pivoted at 70 to bracket 72 mounted on the machine frame, andwhich has its opposite end vertically adjustable by upstanding bolts 74so that the tension in the chain 62 can be adjusted precisely.

The sequence control mechanism 56 comprises a cam 76 which has a camtrack 78 formed in one face thereof which is divided into four sections78-1, 782, 783, and 784. A pair of roller type cam followers 80 and 82is engaged in the cam track 78. The cam follower 80 controls theoperation of the pusher mechanism 46, the tucker assembly 48, and thefolder assembly 50. The cam follower 82 controls the operation of theheat sealing mechanism 52.

Pusher mechanism and stationary sealer The cam follower 80 is carried atapproximately the midpoint of a rocking beam 84 which has one endpivoted at 86 to a bracket 88 depending from the bottom frame 32. At itsopposite end the rocking beam 84 is pivotally connected to a link 90which in turn is pivotally connected to an arm 92 fixed to acountershaft 94 rotatably carried in bearings mounted on the beams 34and 36. Movement of the countershaft 94 is a rocking movement which itobtains from the beam 84 and the cam sections 783 and 784.

Fixed to the shaft 94 is an arm 96 which has its free end connected to along link 98 which is pivotally connected to a link underlying the frameextension 30 and which has its lower end pivotally connected to a motioncompensating lever 102 pivoted to the bottom frame 32 on a bracket 104.At its upper end the link 100 is pivotally connected to the pushermechanism 46.

The pusher mechanism 46 is best seen in FIGS. 1, 2, 3, 5, and 10, andincludes a casting 106 which has an elongated central portion with abore therethrough to receive a guide rod 108 whichis fixedly mounted inthe frame extension 30 and is connected to the top frame 24. The casting106 has a bifurcated depending portion 110 to which the upper end of thelong link 100 is pivotally connected.

The casting also has a pair of arms 112 on the outer ends of which aremounted guide rollers 114. The rollers 114 ride along the undersides ofangle iron guide tracks 116 fixed to the underside of plate 118 of theextension frame 30.

The casting 106 has an upwardly and forwardly ex tending arm 120 whichprojects through a slot 122 in the plate 118, the slot extending thefull length of the extension frame 30. The arm 120 carries a transversebar 124- which has a pusher pad 126 formed on its forward face and whichslidably carries additional pusher pads 128 which are secured to angleshaped members 130. The angle shaped members 130 embrace guide tracks132 which are movable inwardly and outwardly in a manner which will bemore fully explained hereinafter. The guide tracks 132 are carried onpairs of vertical posts 134 at their rear and forward ends, and theposts in turn are secured at their lower ends on arms 136 to anglemembers 138, the latter of which are adjustable inwardly and outwardlyof the longitudinal center of the machine for the purpose ofaccommodating the machine to packages of various widths. The postsextend through transverse slots 141 in the plate 118 (FIG. 1).

The angle shaped members which are connected to the pushers 128 alsoprovide forwardly extending blade-like rear tu-ckers 140 which movealong paths which are immediately to the inside of the guide rails 132and closely adjacent the sides of the tray T. The rear tuckers 140project forwardly and cooperate with the front tuckers and thereforeform a part of the tucker assembly 48. Their function will be describedhereinafter.

At the front of the extension frame 30 is a raised platform 142 underwhich the arm 120 is withdrawn (FIG. 2) and which supports an electricheater element 144 which is used by the operator for the first heatsealing operation of the package wrapping cycle. When a tray T andcontents C is to be wrapped, a sheet of wrapping material W is placedover the package so that it is arranged diagonally of the major axes ofthe package, that is, the diagonal axes of the sheet coincide with themajor and minor axes of the package. The wings of the package extendingforwardly and rearwardly thereof are folded snugly against the contentsC and under the bottom of the tray T and heat sealed together bypressing them momentarily against the heater element 144. The packagethus arranged is placed in position shown in FIG. 2, so that a portionof the underside of the sidewardly extending wings which show mostclearly in FIG. 4 are tucked upwardly against the sides of the tray T bythe rear tuckers 140.

The package is advanced the first quarter machine cycle as the camfollower 80 moves through the cam section 7-8-3 from the position ofFIG. 2 to the position of FIG. 3, thereby depressing the rocking beam 84and rotating the shaft 94 in the clockwise direction. This swings thearm 96 in the clockwise direction and the link 98 rightwardly. The link100 is pivoted in the clockwise direction to advance the pusher assembly46 and the partially wrapped package from the position of FIG. 2 to thatof FIG. 3 and into the tucking, folding, and heat sealing station 40. Atthe same time the folder assembly 50 will be raised from the FIG. 2 tothe FIG. 3 position in a manner to be described.

Folder mechanism and front tuckers The mechanism for operating thefolder assembly 50 is best shown in FIGS. 1, 2, 3, 4, 5, and 9. Fixed tothe shaft 94 is an arm 146 which is identical with the arm 92. The arm146 is pivotally connected to a bifurcated connector 148 whichthreadedly and adjustably receives a long generally vertically extendingrod 150 having a second bifurcated connector 152 at its upper end. Theupper bifurcated connector is pivotally connected to one arm of abellcrank lever 154 which is fixed on a rock shaft 156 journaled inbearings adjacent either and carried by brackets 158 mounted on the topframe 24. It will be noted most clearly from-FIG. 9 that the bellcranklever 154 is connected adjacent one end of the shaft 156 and at theopposite end a similar lever 160 is secured, although this need not be abell crank lever.

Extending between the second arm of the bell crank lever 154 and thelever 160 is a square guide and motion transmitting bar 162 which issecured to the levers 154 and 160.

The shaft 156 slidably supports a pair of U-shaped brackets 164 whichhave arms 166 fixed to the upstanding flanges of the inwardly andoutwardly adjustable and longitudinally extending bars 138. Second arms168 of the bracket 164 are also carried by the rock shaft 156. Betweenthe arms 166 and 168 are folders 170 and front tuckers 172. The folderscomprise arms 174 which may be castings, and may have formed integrallytherewith or welded thereto spacers 176 and 178. The square bar 162slidably extends through the folder arms 174 so that the rocking motionof the bell crank lever 154 is transmitted to the folders 170. Fixed tothe arms 174 are arm extensions 180, the shapes of which can best beseen in FIGS. 2 and 4. The undersides of the extensions are formed witha re-entrant angle 182 which is quite sharp, being approximately 90 withthe sides connected by a curved section 184. The edges of the angle 182and curve 184 are covered with a channel 186 of neoprene or some similarmaterial which slightly frictionally engages the wrapper material todraw it snugly about the contents C and tray T as the folders are movedfrom the dotted to the full line position of FIG. 2, or moved downwardlyand toward the viewer as seen in FIG. 4. The top edges of the extensionarms are formed as flanges 188 to provide a smooth surface over which acurtain, to be described, and the folded down wrapper may be drawnduring the final portion of the wrapping operation.

Each front tucker 172 comprises a long thin blade secured to a spacingjournal 190 freely rotatable on the shaft 156 and is independentlymovable of the folder 170 adjacent thereto. The front tucker 172 isspaced inwardly of the adjacent folder 170 and is spaced therefrom thedistance provided by the spacer element 178 which is carried by thefolder, this spacing being sufficient to permit the passage of thewrapper material W as it is drawn closely about the contents and tray bythe folders 170 as they are moved downwardly during the second portionof the machine cycle.

It should be noted that during the first portion of the machine cyclethe folders are raised from the full line to the dotted line position inFIG. 2, and the front tuckers also move upwardly under the biasingeffect of springs 192 connected between projecting portions 194 of thetuckers and studs 196 carried by the bracket arms 166 or the movable bar138 adjacent thereto. The upward movement of the tucker is limited by astud 198 carried by the bight portion of the bracket 164 which engagesthe rear face of the tucker to terminate its upward movement in theposition most clearly shown in FIG. 5.

The front tucker 172 has in its operative position a plane upper surface200 which is coextensive with a corresponding surface 202 on the reartucker 140-, and the two tuckers have matching angular surfaces 204 and206 so that when they are in operative position (FIG. 5) they present asubstantially unbroken line to the under surface of the tubularprojection of material of wrapper W extending from the package.

It should also be observed that the surface 206 on the front tuckerincludes a portion on the projecting finger section 208 in order toprovide a sufiicient amount of surface so that as the package moves fromleft to right (FIGS. 2, 3, and any material which projects sidewardly,as shown most graphically in FIG. 4, is tucked upwardly and closelyagainst the package and tray T. It will be noted that the tuckers, asshown in FIG. 4, are closely adjacent the sides of the tray T and anymaterial which comes from the bottom of the tray is held against thesides of the tray and drawn tautly thereabout.

The tuckers 172 are depressed from their tucking position, as shown inFIG. 3, to a clearance position, as shown in FIG. 2, by inwardlyprojecting pins 210 carried on the folder arms 174 which engage recessedsurfaces 212 on the tucker blades 172 to the rear of the top surface202, the movement of the tuckcrs to the depressed position beingeffected against the bias of the springs 192. It is necessary to movethe tuckers to this depressed position to permit the heat sealers to gothrough their cycle, as will be explained hereinafter.

Adjustment for package width The assembly of the folders, rear tuckers,and rails 138 is manually adjustable from approximately the longitudinalmidpoint of the machine to accommodate packages of different width sothat the folders and tuckers can be brought into snug side relationshipwith the different sized packages. The arrangement for making thisadjustment is most clearly seen in FIGS. 1, 6, 7, and 9. It includes apair of screws 214 having reversely threaded sections 216 and 218 and anextension 220, journaled in bearings 222 carried by the top frame 24.The threaded sections 216 and 218 extend through nuts 224 secured to theunderside of the long bars 138. The screws and extensions areinterconnected by sprockets 226 fixed to the extensions 220 and a chain228 so that they rotate in the same direction and in unison. The forwardscrew 214 is manually turned by a crank handle 230 to the operatorsright (FIG. 1).

Support rails As the package moves from the plate 118 to the station atwhich the sidewardly projecting wings of the wrapper W are tucked,folded, and heat sealed, it rides on a pair of rails 232 (FIGS. 1, 4, 6,and 7), which are pivotally mounted at 234 on the adjustable bars 138and have springs 236 biasing them to the upward position where thevertical portion of the rail 232 abuts against the outwardly facing edgeof the angle shaped bar 138. The upper portion of the rail is flanged at238 to pro vide the track on which the package rides, as most clearlyseen in FIGS. 4, 6, and 7. The rails 232 are pivotally mounted so thatthey can be tipped out of the way as shown in FIG. 7, to accommodatepassage of the heat sealers.

The package exits on rails 239 fixed to the adjustable base 138.

Movable heat scaling mechanism As noted previously, the heat sealingmechanism is driven from the cam 76 through the cam follower 82. Thisdrive is most clearly seen in FIGS. 2, 3, 6, and 7. The cam follower 82is pivotally mounted at 240 on a stirrup plate 242 which has abifurcated lower end to straddle the shaft 66 (FIGS. 2 and 3). The upperend of the stirrup plate is connected to a rod 244 slidably extendingthrough vertical guides 246 and at its upper end being adjustablyconnected to a crosshead 248. The ends of the crosshead 248 arepivotally connected to a pair of links 250, each of which is turn ispivotally connected to an arm 252 of a bell crank assembly pivoted at254 to a bracket 256 carried by the top frame 24. The second arm 258 ofthe bell crank assembly is connected through adjustable connections to alink 260 which in turn is pivotally connected to a relatively long link262. At its lower end the long link is connected to a motioncompensating lever 264 which is pivotally mounted on a bracket 266carried by the bottom frame 32. The upper end of the link 262 is formedin a Wye 268 with a pivotal connection to a long rod 276 carried by aheater frame 272.

There are a pair of heater frames, one at either side of the path ofpackage movement (FIGS. 1, 6, and 7). Each includes at its outer portiona pair of truck assemblies 274 having rollers 276 which ride in channelshaped tracks 278. The truck assemblies are connected to side member 280which are interconnected and support at their forward ends electricheater elements 282 and a rotatable nose bar 284. A curtain 286 of aheat resistant material such as glass fiber or Teflon coated fabric isanchored at 288 and is draped across the heater 282 and nose bar 284,the anchor 288 extending between the rails 278. The curtain extendsreversely over a roller 290 and its lower end is weighted at 292 to keepthe curtain snug as the heaters are moved from their retracted position(FIG. 6) through a heat sealing cycle to the advanced position (FIG. 7).The rollers 290 are pivotally mounted in brackets carried on angle framemembers 294 which support the rail structure 278.

The purpose of using the curtain is to prevent sliding contact betweenthe heater element 282 and the material of the wrapper W. Somematerials, such as the Pliofilm brand of rubber hydrochloride, have atendency to drag if they are ironed during heat sealing, andconsequently it is essential that this ironing movement be avoided. Onthe other hand, as the curtain 286 moves across this material, ittransmits the heat from the heater 282 to the material without anysliding movement and the heat sealing of the overlapped portions of thewrapper W is effected. It might also be possible to use a roller type ofheater instead of the fiat heater 282, but it is thought that the flatheater is somewhat better inasmuch as it provides a larger area of heatcontact over the surface of the material being heat sealed, andtherefore is more efficient and more positive in its heat sealingoperation.

It may be possible that there are tags W of the wrapper materialprojecting below the package at the conclusion of the heat sealingoperation, and it is desirable that these tags be folded against thebottom of the package and heat sealed against the already presentmaterial. For that purpose there is provided at the outlet end of themachine-the right end as seen in FIGS. 1, 2, and 3 a heater roller 296which extends across the full width of the track way, and this rollerfolds the tag ends W against the bottom of the package and heat sealsthem against the wrapper as the package is ejected from the machineacross a slide bar 298.

Ejector mechanism The package is pushed from the tucking, folding, andheat sealing position (FIGS. 4 and 5) by a forward pusher 300 pivotallymounted and spring biased to upright position on a vertically extendingbracket 302 which is connected to a forwardly extending arm 308connected at its rear to the bifurcated depending portion of the casting106. The forward end of the arm 308 and the lower end of the bracket 302are interconnected and fitted with a roller 310 which rides in a channelshaped track 312 extending the length of the main portion of the machine(FIG. 5). (This track 312 has been omitted from FIG. 1 to show parts ofthe drive mechanism below it.) As the pusher assembly is retracted toclear the area for the operation of the folders, the forward pusher 300is flipped down to pass under the package at the tucking, folding, andheat sealing station.

Operation At the start of the machine cycle, the machine elements are inthe position shown in FIGS. 1 and 2 with the folders and front tuckers172 in the down position, and with pusher assembly 46 and the reartuckers 140 in the retracted position. The operator selects a packageand a wrapper sheet W, and arranges them in front of him. With thewrapper positioned diagonally across the top of the contents C and trayT, he folds and stretches the forward and rearward extending portions ofthe wrapper underneath the tray T so that wings extend sidewardly ingenerally the position shown in FIG. 4. The overlapped portions of thewrapper are heat sealed together by pressing them against the stationaryheater 144 in front of him. The package is then placed between the reartuckers 140 so that a part of the bottom portion of the extendingwrapper wings is brought snugly against the sides of the tray T.

The motor 58 is energized by pressing the start button (eitherincidentally by placing the package or by a separate manual act) andthrough the chain drive and clutch assembly the cam 76 is rotated in thecounterclockwise direction (FIGS. 2 and 3). The cam follower 82 entersthe dwell sections 78-1 and 78-2 of the cam tracks 78 so that the heaterassemblies 52 are retained in their withdrawn position (FIG. 6). Thefollower roller 80 enters the rise section 78-3 of the cam track and thebeam 84 is depressed and through the linkage 90, 92 rocks the shaft 94in the clockwise direction. This rocking movement is transmitted throughthe linkage 96, 98, 100 to the pusher casting 106 which advances thepusher assembly 46 and rear tuckers 140.

At the same time the rock shaft through the linkage 146, 150, and bellcrank 154 and lever 160 raises the folders 170 to the dotted lineposition of FIG. 2. At this time the springs 192 move the front tuckers172 upwardly to the tucking position shown in FIG. 3.

As the package is advanced, the lower portions of the wings of wrappermaterial W slide up the surfaces 206 and are tucked upwardly andinwardly against the sides of the tray T, so that when the package hasbeen advanced to the position shown in FIGS. 3 and 5, the material underthe bottom of the tray is brought tautly against the sides of thepackage by the tucking operation.

Continued rotation of the cam 76 brings the cam follower 82 into thesecond dwell portion 78-2 of the cam track, but it brings the camfollower 80 into the return portion 78-4 of the cam track, therebyraising the rock beam 84. The reverse of the previously describedmovements occurs and as the beam is raised, the shaft 94 is rotated inthe counterclockwise direction so that the pusher assembly 46 and reartuckers 140 are withdrawn. However, this does not disturb the positionof the material inasmuch as the front tuckers 172 maintain their grip onthe wrapper material. At the same time, the folders are brought down byraising the rod 150 and pivoting the bell crank 154 in thecounterclockwise direction through the rocking movement of the shaft 156and the bell crank 154 and lever 160. The neoprene channel 186 on thereentrant edge 182 of the folders engages the upper portion of the wingsof the wrapper material and draws and folds them downwardly tightlyacross the top edge 200 of the tuckers 172. As the folding operation isconcluded, the tuckers 172 are depressed by the folders 170 (FIG. 2),but material once having been folded remains in position and the top ofthe wrapper W is brought tightly across the top of the package contentsC.

The cam follower 80 now enters the dwell portion 78-1 and 78-2 of thecam 76 so that this portion of the machine, the pusher assembly, thefolders, and the tuckers, do not move during the remainder of themachine cycle.

The cam follower 82 enters the rise section 78-3 of the cam track 78 tolift the stirrup 242, rod 244, and crosshead 248 (FIGS. 3, 6, and 7).The lifting movement rocks the bell crank assembly of the arms 252 and258 so as to swing the lower ends of the arms 258 inwardly (FIG. 7).This movement rocks the link 262 and Wye 268 in the inward directionabout the pivot on the motion compensating levers 264. The heater framesare moved inwardly and 10 the nose bars 284 and the curtain 286 engagethe folded down portion of the wrapper W. They wipe this tightly acrossthe bottom of the package and through the action of the heater 282 heatseal these folded under portions of the wrapper against the previouslyfolded under and heat sealed portions.

The final movements of the movable heaters are shown in FIG. 7 and it ispossible that there will be tags W of the wrapper projecting downwardly.

In the last portion of the machine cycle, the cam follower 82 enters thetrack portion 78-4 and lowers the cam follower 82 to reverse themovement of the linkage just described and to retract the heaters to theFIG. 6 position, thereby terminating the machine cycle, deenergizi-ngthe electric circuit, and conditioning the machine for a subsequentoperation.

During subsequent machine cycles, the packages as thus wrapped arepushed to the exit of the machine by the front pushers 300 as a newpackage is moved to the tucking, folding, and heat sealing positions ofFIGS. 3, 4, 5, and 7. The package as it is removed from the machineslides over the roller 296 which presses the tags W against the bottomof the package and heat seals them against the material already there.In the event the package is small, there may be one or more in the pathexiting from the machine, but the material is not burned since the heatis not high enough and the contact between the roller 296 and thewrapper material is minimum. The subsequent packages will push otherpackages across the exit bar 298 into whatever receptacle or conveyor isat the outlet of the machine.

It will be seen from the foregoing description that the objectives whichwere claimed for this invention at the outset of the specification arefully attained by the structure and method described.

While a preferred embodiment of the invention has been shown anddescribed, it will be apparent that numerous modifications andvariations thereof may be made therein without departing from theunderlying principles of the invention. It is therefore desired, by thefollowing claims, to include within the scope of the invention all suchvariations and modifications by which substantially the results of thisinvention may be obtained through the use of substantially the same orequivalent means.

What is claimed as new and desired to be secured by United StatesLetters Patent is:

1. In a machine for wrapping packages of the type including arectangular tray'and irregularly shaped contents within the tray with asquare sheet of heat scalable material wherein the sheet is initiallywrapped about the package with its diagonal axes generally coincidentwith the major and minor axes of the tray and two opposite corners ofthe sheet are folded under and against the bottom of the tray and sealedtogether so that the sheet is secured tautly about the package withgenerally tubular extensions projecting at opposite sides, thecombination comprising, means for advancing the package in initiallywrapped condition to a final wrapping position, two pairs of tuckingblades closely arranged at the sides of the package and engageable withthe underportions of the projecting tubular wrapper to fold those partsupwardly against the sides of the tray, one of said pairs being mountedon and movable with said advancing means and the other being pivotallymounted on the machine, side folding means folding the projectingtubular portions downwardly over said pivotally mounted tucking blades,said tucking blades and said folding means being removed from tuckingand folding positions respectively without disturbing the tucked andfolded tubular sheet portions, movable heat sealing means folding thetucked and folded sheet portions against the underside of the traysubsequent to the removal of said tucking blades and said folding meansand sealing them to the initially folded and sealed portions, rotatablecam means, power means for rotating said cam means, and linkage meansconnect- 1 1 ing said advancing means, said tucking blades, said foldingmeans, and said movable heat sealing means with said cams meanssequentially to operate all of said means.

2. The combination set forth in claim 1, including means biasing saidpivotally mounted tucking blades toward tucking position, and stop meanslimiting the movement of said pivotally mounted tucking blades to and attucking position.

3. The combination set forth in claim 1, including means carried by saidfolding means engageable with said pivotally mounted tucking blades topivot said tucking blades from tucking position at the end of a foldingoperation.

4. The combination set forth in claim 1, wherein said folding meanscomprises a pair of pivotally mounted arms closely arranged at the sidesof the package to the outside of said tucking blades.

5. The combination set forth in claim 4, wherein said arms are bladelikeand are formed with a sharp reentrant angle on their undersides whichengages and downwardly folds the tubular extensions of the wrapper tautover said tucking means.

6. The combination set forth in claim 5, including a covering offriction material on the edges of said reentrant angle frictionally andslidably to engage the wrapper sheet so as tightly to draw it over thetray and contents.

7. The combination set forth in claim 1, including means connected tosaid tucking and said folding means to move them transversely thereby toaccommodate packages of varying widths.

S. The combination set forth in claim 1, wherein said cam means has asingle cam track, and said linkage means includes a first cam follower,linkage connecting said cam follower to rotate a rock shaft, linkageconnecting said rock shaft to advance and retract said package advancingmeans, and other linkage connecting said rock shaft to operate saidfolding means.

9. The combination set forth in claim 1, wherein said movable heatsealing means includes a pair of movable frames arranged at either sideof the package in said final wrapping position, and a heating elementcarried by said frames at the forward portions thereof.

10. The combination set forth in claim 9, including a curtain of heatresistant material trained over each of said heating elements, meansanchoring one end of each curtain, and means placing a tension on saidcurtain, so that as said heating elements are advanced the curtains arenonslidably pressed against the downwardly folded portions of thewrapper sheet to fold them against the underside of the tray.

11. The combination set forth in claim 10, including a forward nose barat the forward edge of each frame, and a direction reversing rollerbelow each frame, said curtains being trained over said nose bar andsaid rollers.

12. The combination set forth in claim 1, wherein said cam means has asingle cam track, and said linkage means includes a second cam follower,a rectilinearly movable crosshead connected to said cam follower, anddual linkage connected between said cam follower and said movable heatsealing means.

13. In a machine for wrapping packages of the type including arectangular tray and irregularly shaped contents within the tray with asquare sheet of heat sealable material wherein the sheet is initiallywrapped about the package with its diagonal axes generally coincidentwith the major and minor axes of the tray and two opposite corners ofthe sheet are folded under and against the bottom of the tray and sealedtogether so that the sheet is secured tautly about the package withgenerally tubular extensions projecting at opposite sides, thecombination comprising, means for advancing the package in initiallywrapped condition to a final wrapping position, front tucking meansengageable with the forward part of the underportions of the projectingtubular wrapper to fold those parts upwardly against the sides of thetray, rear tucking means connected to and movable with said advancingmeans and engageable with the rearward parts of the underportions of theprojecting tubular wrapper to fold those parts upwardly against thesides of the tray, side folding means folding the projecting tubularportions including the tucked forward and rearward parts thereof oversaid front tucking means as said advancing means and said rear tuckingmeans are retracted, said front tucking means and said folding meansbeing removed from tucking and folding positions respectively withoutdisturbing the tucked and folded tubular sheet portions, movable heatsealing means folding the tucked and folded sheet portions against theunderside of the tray subsequent to the removal of said front tuckingmeans and said folding means and sealing them to the initially foldedand sealed portions, rotatable cam means, power means for rotating saidcam means, and linkage means connecting said advancing means, said fronttucking means, said rear tucking means, said folding means, and saidmovable heat sealing means with said cam means sequentially to operateall of said means.

References Cited UNITED STATES PATENTS 2,917,885 12/1959 tremke et al.53-206 2,975,572 3/1961 Wertheimer 53-206 2,981,043 4/1961 Arvidson53206 3,031,817 5/1962 Parks 53-206 WILLIAM W. DYER, JR., PrimaryExaminer.

G. Y. CUSTER, JR., Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 ,378,990" April 23, 1968 Henry Lowell Byland It is hereby certified thaterror appears in the above numbered patent requiring correction and thatthe said Letters Patent should read as corrected below. r I

Column 7, line 72, "is", first occurrence, should read in Column 10}lines 67 to 69, cancel "removed from tucking and folding positionsrespectively without disturbing the tucked and folddtub'ular sheet";line 70, cancel "portions" and insert ekmovabl during the operation ofsaid folding means to positions below the plane of the underside of thepackage being wrapped, thereby to hold the tucked and folded tubularsheet portions in'folded'condition lines 72 and 73, cancel "subsequentto the removal of said tucking blades and said folding means" and insertwhile said pivotally mounted tuckingblades"and'said folding means are insaid last described positions Colinhh'll, line 29, after "tucking"insert blades Column 12, lines 31 to 33, cancel "removed from tuckingand foldin positions respectively without disturbing" and insert--movable to positions below the plane of the underside of the packagebeing wrapped to retain line 33, before the comma insert -s in foldedcondition lines 35 to 37, cancel "subsequent to the removal of saidfront tucking means and said folding means" and insert while said fronttucking means and said folding means are in said last describedpositions Signed and sealed this 14th day of October 1969.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting OfficerCommissioner of Patents

